Vehicle light system

ABSTRACT

A present invention provide a vehicle light system which prevents low-beam headlights from being forgotten to turn on while a vehicle is traveling and is able to turn off the low-beam headlights when it is not necessary, a rotation position of a light switch includes an AUTO position, a SMALL position, and an OFF position, the light switch includes a momentary mechanism which returns a position to the AUTO position when the position is changed to the OFF position or the SMALL position, lights include the low-beam headlights and position lights, the AUTO position allows the low-beam headlights and the position lights to turn on or off depending on a brightness outside the vehicle, and a light control unit turns off the low-beam headlights and turns on the position lights when the rotation position is set to the AUTO position, the brightness outside the vehicle is lower than a predetermined value, a speed is lower than a first predetermined speed, and the rotation position is then changed to the SMALL position or the OFF position.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuing application of and claimspriority under 35 U.S.C. § 120 to U.S. patent application Ser. No.17/198,599, filed Mar. 11, 2021, and claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2020-044878, filed Mar. 16, 2020,the contents of which are hereby incorporated by reference in theirentirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a light system for vehicles.

2. Description of the Related Art

Japanese Patent Laid-open Publication No. 2005-170217 discloses a lightswitch including an automatic light operating position enabling anautomatic light function that automatically turns lights of a vehicle onor off depending on illuminance outside the vehicle.

In some vehicles on the market, a combination switch as the light switchhas a following structure. The light switch is able to be set to OFF,AUTO, SMALL, and HEADLIGHT positions. When the light switch is set tothe AUTO position, low-beam headlights and position lights (in otherwords, clearance lamp) are turned on or off depending on the illuminanceoutside the vehicle. Furthermore, such a vehicle performs the followingoperation when the light switch is set to the OFF position (to turn offthe low-beam headlights and position lights). The light switchautomatically returns from the OFF position to the AUTO position due toa momentary mechanism of the light switch. This means that the vehicleis designed not to travel while the light switch is in the OFF position.

When the light switch is set to the SMALL position, the low-beamheadlights are turned off, and the position lights are turned on. Whenthe light switch is set to the HEADLIGHT position, the low-beamheadlights are turned on, and the position lights are also turned on.

The aforementioned technique is designed not to allow the vehicle totravel while the light switch is set in the OFF position, whicheffectively prevents the vehicle from being forgotten to turn on thelight. However, the technique still allows the vehicle to travel whilethe light switch is set in the SMALL position. The vehicle therefore cantravel with the low-beam headlights off. Thus, the technique has roomfor improvement in preventing the vehicle from being forgotten to turnon the low-beam headlights.

The low-beam headlights may be designed to be normally on when thevehicle is traveling (at least while it is so dark outside the vehiclethat the low-beam headlights need to be on).

According to the aforementioned design, the low-beam headlights areturned on even when the vehicle's speed is low, for example, for parkingthe vehicle into a garage. At driving the vehicle at low speed, it maybe assumed that there are various objects, such as walls and obstacles,around or near the vehicle. In such a case, light from the low-beamheadlights is reflected by the objects and can interfere with driving ofthe vehicle. It is therefore preferable that the low-beam headlights beturned on depending on the vehicle's situation.

SUMMARY OF THE INVENTION

The present invention has been made to solve the above problems andmakes it an object thereof to provide a vehicle light system whichprevents the low-beam headlights from being forgotten to turn on whilethe vehicle is traveling and is able to turn off the low-beam headlightswhen it is not necessary.

According to the present invention, a light system for a vehicleincludes: a combination switch set to a rotation position to berotationally changed for switching modes of a light that providesillumination outside; a photosensor configured to detect brightnessoutside the vehicle; and a speed sensor configured to detect speed ofthe vehicle, in which the rotation position includes an AUTO position, aSMALL position, and an OFF position, the combination switch includes amechanism which returns the position to the AUTO position when theposition is changed to the OFF position or the SMALL position, thelights include low-beam headlights and position lights, and the AUTOposition allows the low-beam headlights and position lights to turn onor off depending on the brightness outside the vehicle detected by thephotosensor. The light system further includes: a light control unitconfigured to turn off the low-beam headlights and to turn on theposition lights when the rotation position is set to the AUTO position,the brightness outside the vehicle detected by the photosensor is lowerthan a predetermined value, the speed detected by the speed sensor islower than a first predetermined speed, and the rotation position isthen changed to the SMALL position or the OFF position.

The present invention can provide a vehicle light system which preventsthe low-beam headlights from being forgotten to turn on while thevehicle is traveling and is able to turn off the low-beam headlightswhen it is not necessary.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the configuration of a vehicle lightsystem according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a first process executed by the vehiclelight system according to the embodiment of the present invention.

FIG. 3 is a flowchart showing a second process executed by the vehiclelight system according to the embodiment of the present invention.

FIG. 4 is a flowchart showing a third process executed by the vehiclelight system according to the embodiment of the present invention.

FIG. 5 is a flowchart showing a fourth process executed by the vehiclelight system according to the embodiment of the present invention.

FIG. 6 is a flowchart showing the fourth process executed by the vehiclelight system according to the embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENT

An embodiment of the present invention will be hereinafter described indetail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing the configuration of a vehicle lightsystem 1 according to the embodiment. The vehicle light system 1 ismounted in a vehicle for use. The vehicle light system 1 includes alight switch 11 provided at a predetermined position near the driver'sseat of the vehicle. The light switch 11 is a combination switch that isrotated to switch plural modes of lights that provide illuminationoutside from the vehicle. The light switch 11, which is substantiallycylindrical, is manually rotated in the circumferential direction toswitch the plural (four in this embodiment) modes of lights.

The vehicle light system 1 includes four types of rotation positions,including an OFF position 12, an AUTO position 13, a SMALL position 14,and a HEADLIGHT position 15. On the lateral surface of the light switch11, letters or symbols indicating these four positions, including theOFF position 12, AUTO position 13, SMALL position 14, and HEADLIGHTposition 15, are displayed. These letters or symbols are aligned in thecircumferential direction on the lateral surface of the light switch 11.Specifically, the HEADLIGHT position 15, AUTO position 13, SMALLposition 14, and OFF position 12 are indicated in this order, startingfrom the near side of the driver. When the light switch 11 is manuallyrotated in the circumferential direction to set one of those positionsto a reference position 16, the mode corresponding to the position setto the reference position 16 works. For example, “AUTO” mode works whenthe AUTO position 13 is set to the reference position 16 as illustratedin FIG. 1 . “SMALL” mode works when the symbol for the SMALL position 14is set to the reference position 16. “OFF” mode works when the OFFposition 12 is set to the reference position 16. “HEADLIGHT” mode workswhen the HEADLIGHT position 15 is set to the reference position 16.

Hereinafter, the modes corresponding to the respective positions of thelight switch 11 will be described below. The vehicle includes headlightswhich are located in the front of the vehicle and provide illuminationahead of the vehicle. The headlights include low-beam headlights 21 andhigh-beam headlights 23. The illumination distance of the high-beamheadlights 23 is longer than that of the low-beam headlights 21. Thevehicle further includes position lights 22 which are located in thefront and rear of the vehicle and provide illumination around thevehicle. The illumination distance of the position lights 22 is shorterthan that of the low-beam headlights 21. FIG. 1 illustrates only onelow-beam headlight 21 and one high-beam headlight 23 for convenience,but a typical vehicle includes plural low-beam headlights 21 and pluralhigh-beam headlights 23 (the same applies to the position lights 22). Inthe “OFF” mode, basically, the low-beam headlights 21 and positionlights 22 mounted on the vehicle are all turned off, but variouscontrols are performed for turning on or off of the low-beam headlights21 and position lights 22 as described later.

This specification describes turning on and off of the low-beamheadlights 21. A typical vehicle also includes the high-beam headlights23. Switching between the low-beam headlights 21 and high-beamheadlights 23 is performed with a not-illustrated switch that isdifferent from the light switch 11. In a situation where the setting ofthe not-illustrated switch is the high-beam headlights 23, operations ofturning on or off the high-beam headlights 23 correspond to operationsof turning on or off the low-beam headlights 21 in this specification.

In recent years, some vehicles include a controller which automaticallyswitches between the low-beam headlights 21 and high-beam headlights 23by determining the situation ahead of the vehicle (whether there is anoncoming vehicle ahead, for example). For such vehicles, description ofturning on or off of the low-beam headlights 21 in this specificationmeans turning on or off of the low-beam headlights 21 or high-beamheadlights 23 automatically selected by the controller.

The modes will be further described. In the AUTO mode, various controlsare performed for turning on or off of the low-beam headlights 21 andposition lights 22 as described later. Specifically, the low-beamheadlights 21 and position lights 22 are turned on or off depending onwhether the brightness outside the vehicle, which is detected with aphotosensor 24, is lower than a predetermined value as described later.

The brightness detected with the photosensor 24 may be evaluated withtwo thresholds of different levels. When the detected brightness is lessthan the higher threshold (brighter), only the position lights 22 areturned on, and when the detected brightness is less than the lowerthreshold (darker), the low-beam headlights 21 and position lights 22are both turned on.

In the “SMALL” mode, basically, the low-beam headlights 21 are turnedoff, and the position lights 22 are turned on. In the “HEADLIGHT” mode,basically, the low-beam headlights 21 are turned on, and the positionlights 22 are turned on. In the “SMALL” mode, various controls areperformed for turning on or off of the low-beam headlights 21 andposition lights 22 as described later.

On the light switch 11 capable of changing the modes described above,the aforementioned positions for setting the respective modes aredisposed in the following manner. On the lateral surface of the lightswitch 11, the AUTO position 13 is indicated. On one side of the AUTOposition 13 in the circumferential direction, or on the opposite side ofthe AUTO position 13 from the driver in this embodiment, the SMALLposition 14 is indicated. On the opposite side of the SMALL position 14from the driver, the OFF position 12 is indicated. On the other side ofthe AUTO position 13 in the circumferential direction, or on thedriver's side of the AUTO position 13 in this embodiment, the HEADLIGHTposition 15 is indicated. When the light switch 11 is moved to any ofthese positions, the light switch 11 gives a click feeling to thedriver's hand by a publicly-known means.

The light switch 11 includes a momentary mechanism 36 (mechanism). Themomentary mechanism 36 is a publicly-known structure including a torsionspring and the like. When the driver moves the light switch 11 to theOFF position 12 or SMALL position 14, the momentary mechanism 36 returnsthe light switch 11 to the AUTO position 13 with spring force of thetorsion spring and the like. When the driver moves the light switch 11to the HEADLIGHT position 15, the momentary mechanism 36 does not workso that the light switch 11 remains in the HEADLIGHT position 15.

The light switch 11 is connected to a driving circuit 32. The drivingcircuit 32 notifies a controller 31 of which of the HEADLIGHT position15, AUTO position 13, SMALL position 14, and OFF position 12 is set tothe reference position 16 as a control signal. The controller 31 is acontrol apparatus mainly composed of a microcomputer, for example.

The controller 31 is connected to the photosensor 24 described abovethrough a sensor circuit 34 as an interface and to a speed sensor 33,which detects speed of the vehicle, through a sensor circuit 35 as aninterface. The controller 31 is connected to a parking brake sensor 63through a sensor circuit 64. The parking brake sensor 63 detects on oroff of a parking brake (not illustrated) of the vehicle. The controller31 is connected to a park-range sensor 65 though a sensor circuit 66.The park-range sensor 65 detects on or off of a park range of a gearshifter (not illustrated) of the vehicle. These sensors and controller31 do not need to be directly connected and may communicate each otherthrough a controller area network (CAN).

The controller 31 is connected to the low-beam headlights 21, positionlights 22, and high-beam headlights 23 through lighting circuits 51 to53 as interfaces, respectively. The low-beam headlights 21, positionlights 22, and high-beam headlights 23 respectively include plurallow-beam headlights 21, plural position lights 22, and plural high-beamheadlights 23 unlike those illustrated. The lighting circuits 51 to 53are supplied with electric power from a not-illustrated battery mountedon the vehicle to illuminate the low-beam headlights 21, position lights22, and high-beam headlights 23.

When the light switch 11 is in the AUTO position 13, the low-beamheadlights 21, position lights 22, and high-beam headlights 23 turn onor off based on the control signal from the controller 31. When thelight switch 11 is in the OFF position 12, SMALL position 14, orHEADLIGHT position 15, the low-beam headlights 21, position lights 22,and high-beam headlights 23 also turn on or off based on the controlsignal from the controller 31.

The controller 31 operates based on a predetermined program to executethe functions of a light control unit 41, a travel distance calculationunit 42, and a failure detection unit 43. The light control unit 41controls turning on and off of the low-beam headlights 21 and positionlights 22 depending on the situation of the vehicle. The travel distancecalculation unit 42 calculates a distance (travel distance) traveled bythe vehicle from a certain point to another point. The travel distancecalculation unit 42 determines the travel distance by adding up vehiclespeeds received from the speed sensor 33 at regular intervals. Thefailure detection unit 43 detects whether the sensors illustrated inFIG. 1 have failed.

FIGS. 2 to 6 are flowcharts of processes executed by the light controlunit 41. FIGS. 2 to 4 are flowcharts for explaining first, second, andthird processes, respectively. FIGS. 5 and 6 are flowcharts forexplaining a fourth process. FIGS. 5 and 6 illustrate the fourth processof a series of processing in two flowcharts with connectors indicated bycircled numbers. The first to fourth processes individually operate inparallel on the microcomputer constituting the controller 31. While theignition switch (not illustrated) of the vehicle is on, one of the firstto fourth processes is executed to determine whether to turn on or offthe low-beam headlights 21 and position lights 22 and accordingly turnon or off the low-beam headlights 21 and position lights 22. In thefollowing description, first, second, third, and fourth predeterminedspeeds satisfy the relationship of: second predetermined speed≥firstpredetermined speed>fourth predetermined speed≥third predeterminedspeed.

First, the first process illustrated in FIG. 2 will be described. In thefirst process, the failure detection unit 43 determines whether afailure is detected in the speed sensor 33, or the speed sensor 33 isdetected to normally operate without failure (S1). As a way to detect afailure of the speed sensor 33, for example, the failure detection unit43 determines that a failure is detected in the speed sensor 33 when thecontroller 31 does not receive a predetermined signal that thecontroller 31 is designed to receive when the speed sensor 33 isnormally operating. When no failure is detected in the speed sensor 33(Yes in S1), the light control unit 41 determines whether the brightnessoutside the vehicle detected with the photosensor 24 is lower than apredetermined value (S2). When the brightness outside the vehicledetected with the photosensor 24 is lower than the predetermined value(Yes in S2), the light control unit 41 determines whether the AUTOposition 13 is set to the reference position 16 in the light switch 11(S3). When the AUTO position 13 is set to the reference position 16 (Yesin S3), the light control unit 41 determines whether current speed ofthe vehicle detected by the speed sensor 33 is lower than the firstpredetermined speed (S4). When the current speed of the vehicle detectedby the speed sensor 33 is lower than the first predetermined speed (Yesin S4), the light control unit 41 determines whether the light switch 11is moved to the SMALL position 14 or OFF position 12 (S5). When thelight switch 11 is moved to the SMALL position 14 or OFF position 12(Yes in S5), the light control unit 41 turns off the low-beam headlights21 and turns on the position lights 22 (S6). The light control unit 41then returns the process. When the driver releases his/her hand from thelight switch 11 after moving the light switch 11 to the SMALL position14 or OFF position 12, the AUTO position 13 returns to the referenceposition 16 in the light switch 11 by the momentary mechanism 36.

On the other hand, when the brightness outside the vehicle is not lowerthan the predetermined value (No in S2), when the light switch 11 is notset to the AUTO position 13 (No in S3), when the speed of the vehicle isnot less than the first predetermined speed (No in S4), or when thelight switch 11 is not moved to the SMALL position 14 or OFF position 12(No in S5), the light control unit 41 returns the process to S1. Thedeterminations of S1 to S4 may be executed in a different order.

When a failure is detected in the speed sensor 33 in S1 (No in S1), thelight control unit 41 determines whether the brightness outside thevehicle detected by the photosensor 24 is lower than a predeterminedvalue (S66). When the brightness outside the vehicle detected by thephotosensor 24 is lower than the predetermined value (Yes in S66), thelight control unit 41 turns on the low-beam headlights 21 and positionlights 22 (S11) and returns the process. In this case, even if the lightswitch 11 is moved to the SMALL position 14 or OFF position 12, thelow-beam headlights 21 and position lights 22 remain on.

When the brightness outside the vehicle is not lower than thepredetermined value (No in S66), the light control unit 41 returns theprocess to S1.

Next, the second process illustrated in FIG. 3 will be described. Thelight control unit 41 first determines whether the low-beam headlights21 are turned off through the processing of S6 described above orprocessing of S27 or S36 described later while the position lights 22are turned on (S51). For example, when the low-beam headlights 21 areturned off in S6 described above while the position lights 22 are turnedon (Yes in S51), the light control unit 41 goes to S7; and otherwise (Noin S51), the light control unit 41 returns to S51.

In S7, the light control unit 41 determines whether the current speed ofthe vehicle detected by the speed sensor 33 is equal to or higher thanthe second predetermined speed. The second predetermined speed is athreshold to determine whether the vehicle speeds up from crawling speedto traveling speed. The second predetermined speed is equal to or higherthan the first predetermined speed. When the vehicle speed is equal toor higher than the second predetermined speed (Yes in S7), the lightcontrol unit 41 turns on the low-beam headlights 21 and position lights22 (S52). When the vehicle speed is lower than the second predeterminedspeed (No in S7), the travel distance calculation unit 42 calculates thedistance (travel distance) traveled since the low-beam headlights 21 areturned off (since the low-beam headlights 21 are turned off in S6, forexample) and determines whether the travel distance is equal to orlonger than a predetermined distance (S8). The travel distance isaccumulated until reaching the predetermined distance even though thevehicle stops many times. After reaching the predetermined distance (Yesin S8), the accumulated travel distance is reset when the ignitionswitch (not illustrated) of the vehicle is turned off. When the traveldistance is equal to or longer than the predetermined distance (Yes inS8), the light control unit 41 turns on the low-beam headlights 21 andposition lights 22 (S52).

When the travel distance is shorter than the predetermined distance (Noin S8), the light control unit 41 determines whether the light switch 11is moved again to the SMALL position 14 (S9) after the low-beamheadlights 21 are turned off according to Yes determined in S5 in FIG. 2(S6). When the light switch 11 is moved to the SMALL position 14 (Yes inS9), the light control unit 41 turns on the low-beam headlights 21 andposition lights 22 (S52). When the light switch 11 is not moved to theSMALL position 14 (No in S9), the light control unit 41 determineswhether the light switch 11 is moved to the OFF position 12 (S10). Whenthe light switch 11 is moved to the OFF position 12 (Yes in S10), thelight control unit 41 turns off the low-beam headlights 21 and turns onthe position lights 22 (S53). When the light switch 11 is not moved tothe OFF position 12 (No in S10), the light control unit 41 returns thesecond process. If the driver releases his/her hand from the lightswitch 11 after moving the light switch 11 to the SMALL position 14 orOFF position 12, the AUTO position 13 returns to the reference position16 in the light switch 11 by the momentary mechanism 36.

Next, the third process illustrated in FIG. 4 will be described. Thelight control unit 41 first determines whether the current speed of thevehicle is lower than the third predetermined speed (S12). The thirdpredetermined speed is a threshold to determine whether the vehiclewhich has been moving at crawling speed is substantially stopped. Thethird predetermined speed is lower than the first and secondpredetermined speeds. When the vehicle speed is lower than the thirdpredetermined speed (Yes in S12), the light control unit 41 thendetermines with the parking brake sensor 63 and park-range sensor 65whether at least one of the parking brake and park range is on (S13).When at least one of the parking brake and park-range is on (Yes inS13), the light control unit 41 determines whether the brightnessoutside the vehicle detected by the photosensor 24 is lower than thepredetermined value (S14). When the brightness outside the vehicledetected by the photosensor 24 is lower than the predetermined value(Yes in S14), the light control unit 41 determines whether the AUTOposition 13 is set to the reference position 16 in the light switch 11(S15). When the AUTO position 13 is set to the reference position 16(Yes in S15), the failure detection unit 43 determines whether a failureis detected in the parking brake sensor 63 or park-range sensor 65, orthe parking brake sensor 63 and the park-range sensor 65 are detected tonormally operate without failure (S16). The determination for thisfailure detection may be performed depending on whether the controller31 receives signals which the controller 31 is designed to receive fromthe parking brake sensor 63 and park-range sensor 65 when these sensorsare operating normally. When at least one of the parking brake sensor 63and park-range sensor 65 is determined to have failed (No in S16), thelight control unit 41 turns on the low-beam headlights 21 and positionlights 22 (S17). The determinations of S12 to S16 may be executed in adifferent order.

When the light control unit 41 determines that neither the parking brakesensor 63 nor park-range sensor 65 has failed (Yes in S16), the lightcontrol unit 41 determines whether the low-beam headlights 21 are turnedoff in S6 or S53 while the position lights 22 are turned on (S18). Whenthe low-beam headlights 21 are turned off in S6 or S53 while theposition lights 22 are turned on (Yes in S18), the light control unit 41turns off the low-beam headlights 21 and turns on the position lights 22(S54), and otherwise (No in S18), the light control unit 41 turns on thelow-beam headlights 21 and position lights 22 (S55). After S54 and S55are processed, the light control unit 41 returns to the third process.

Next, the fourth process illustrated in FIGS. 5 and 6 will be described.The light control unit 41 first determines whether the low-beamheadlights 21 and position lights 22 are turned on in S55 (S56). Whenthe low-beam headlights 21 and position lights 22 are turned on in S55(Yes in S56), the light control unit 41 determines whether the lightswitch 11 is moved to the SMALL position 14 (S20). When the light switch11 is moved to the SMALL position 14 (Yes in S20), the light controlunit 41 turns off the low-beam headlights 21 and turns on the positionlights 22 (S21). When the light switch 11 is not moved to the SMALLposition 14 in S20 (No in S20), the light control unit 41 determineswhether the light switch 11 is moved to the OFF position 12 (S29).

When both the low-beam headlights 21 and the position lights 22 are notturned on in S55 (No in S56), the light control unit 41 determineswhether the low-beam headlights 21 are turned off in S54 while theposition lights 22 are turned on (S57). When the low-beam headlights 21are turned off in S57 while the position lights 22 are turned on (Yes inS57), or when the low-beam headlights 21 are turned off in S21 while theposition lights 22 are turned on, the light control unit 41 determineswhether the light switch 11 is moved to the OFF position 12 (S22).

When the light switch 11 is moved to the OFF position 12 in S29 or S22(Yes in S29, Yes in S22), the light control unit 41 turns off thelow-beam headlights 21 and position lights 22 (S23). When the lightswitch 11 is not moved to the OFF position 12 in S29 (No in S29), thelight control unit 41 advances the process to S30 (FIG. 6 ). When thelight switch 11 is not moved to the OFF position 12 in S22 (No in S22),the light control unit 41 advances the process to S33 (FIG. 6 ). Thedeterminations in S20 and S29 may be changed.

Following S23, the light control unit 41 determines whether the lightswitch 11 is moved to the SMALL position 14 (S24). When the light switch11 is moved to the SMALL position 14 (Yes in S24), the light controlunit 41 returns the process to S21. When the light switch 11 is notmoved to the SMALL position 14 (No in S24), the light control unit 41determines with the parking brake sensor 63 and park-range sensor 65whether both of the parking brake and park range are off (S25). Whenboth of the parking brake and park range are off (Yes in S25), the lightcontrol unit 41 turns off the low-beam headlights 21 and turns on theposition lights 22 (S27).

When at least one of the parking brake and park range is on (No in S25),the light control unit 41 determines with the speed sensor 33 whetherthe current speed of the vehicle is equal to or higher than the fourthpredetermined speed (S26). The fourth predetermined speed is a thresholdto determine whether the vehicle which has been substantially stoppedstarts to move at crawling speed. The fourth predetermined speed islower than the first and second predetermined speeds and is equal to orhigher than the third predetermined speed. When the speed of the vehicleis equal to or higher than the fourth predetermined speed (Yes in S26),the light control unit 41 turns off the low-beam headlights 21 and turnson the position lights 22 (S27).

When the speed of the vehicle is lower than the fourth predeterminedspeed (No in S26), the light control unit 41 determines whether thelight switch 11 is moved to the OFF position 12 (S28). When the lightswitch 11 is moved to the OFF position 12 (Yes in S28), the lightcontrol unit 41 turns on the low-beam headlights 21 and position lights22 (S60) and then returns the process to S20 (FIG. 5 ). When the lightswitch 11 is not moved to the OFF position 12 (No in S28), the lightcontrol unit 41 returns the process to S24. The determinations of S25and S26 may be executed in a different order. Furthermore, thedeterminations of S24, (S25, S26), and S28 may be executed in adifferent order.

In FIG. 6 , when the light switch 11 is not moved to the OFF position 12in S29 described above in FIG. 5 (No in S29), the light control unit 41determines with the parking brake sensor 63 and park-range sensor 65whether both of the parking brake and park range are off (S30). Whenboth of the parking brake and park range are off (Yes in S30), the lightcontrol unit 41 turns on the low-beam headlights 21 and position lights22 (S32) and then returns the process.

When at least one of the parking brake and park range is on (No in S30),the light control unit 41 determines with the speed sensor 33 whetherthe current speed of the vehicle is equal to or higher than the fourthpredetermined speed (S31). The determinations of S30 and S31 may beexecuted in a different order. When the current speed of the vehicle isequal to or higher than the fourth predetermined speed (Yes in S31), thelight control unit 41 turns on the low-beam headlights 21 and positionlights 22 (S32) and returns the process. When the current speed of thevehicle is lower than the fourth predetermined speed (No in S31), thelight control unit 41 turns on the low-beam headlights 21 and positionlights 22 (S58) and returns the process to S20 in FIG. 5 .

When the light switch 11 is not moved to the OFF position 12 in S22described above in FIG. 5 (No in S22), in FIG. 6 , the light controlunit 41 determines whether the light switch 11 is moved to the SMALLposition 14 (S33). The determinations of S22 and S33 may be executed ina different order. When the light switch 11 is moved to the SMALLposition 14 (Yes in S33), the light control unit 41 turns on thelow-beam headlights 21 and position lights 22 (S59) and then returns theprocess to S20 in FIG. 5 .

When the light switch 11 is not moved to the SMALL position 14 andremains in the AUTO position 13 (No in S33), the light control unit 41determines with the parking brake sensor 63 and park-range sensor 65whether both of the parking brake and park range are off (S34). Whenboth of the parking brake and park range are off (Yes in S34), the lightcontrol unit 41 turns off the low-beam headlights 21 and turns on theposition lights 22 (S36). The light control unit 41 then returns theprocess. When at least one of the parking brake and park range is on (Noin S34), the light control unit 41 determines with the speed sensor 33whether the current speed of the vehicle is equal to or higher than thefourth predetermined speed (S35). The determinations of S34 and S35 maybe executed in a different order. When the current speed of the vehicleis equal to or higher than the fourth predetermined speed (Yes in S35),the light control unit 41 turns off the low-beam headlights 21 and turnson the position lights 22 (S36). The light control unit 41 then returnsthe process. When the current speed of the vehicle is lower than thefourth predetermined speed (No in S35), the light control unit 41returns the process to S21 in FIG. 5 .

Not described in the flowcharts illustrated above, when the light switch11 is in the HEADLIGHT position 15, the controller 31 maintains thelow-beam headlights 21 and position lights 22 being turned on. This maybe implemented by switching of a certain switching circuit, instead of aprocess executed by the controller 31.

The operation effects of the aforementioned vehicle light system 1 willbe described.

The light switch 11 of the vehicle light system 1 is provided with themomentary mechanism 36. The light switch 11 thereby returns to the AUTOposition 13 when the driver releases his/her hand from the light switch11 after moving the light switch 11 to the OFF position 12 or SMALLposition 14. This prevents the light switch 11 from remaining in the OFFposition 12 or SMALL position 14 and leaving necessary lights off.

However, the driver can hold the light switch 11 with his/her hand tokeep the position of the light switch 11 set to the OFF position 12 orSMALL position 14. The controller 31 therefore controls turning on andoff of the low-beam headlights 21 and position lights 22 as describedabove when the position of the light switch 11 is set to the OFFposition 12 or SMALL position 14.

The light control unit 41 turns off the low-beam headlights 21 and turnson the position lights 22 (S6) when the AUTO position 13 is set to thereference position 16 in the light switch 11 (Yes in S3), the brightnessoutside the vehicle is lower than the predetermined value (Yes in S2),the current speed of the vehicle is lower than the first predeterminedspeed (Yes in S4), and the position of the light switch 11 is changed tothe SMALL position 14 or OFF position 12 (Yes in S5). When the vehicleis crawling in semi-darkness outside, the driver can turn off thelow-beam headlights 21 unwanted by changing the position of the lightswitch 11 to the OFF position 12 or SMALL position 14.

When the low-beam headlights 21 are turned off in S6, S27, or S36 whilethe position lights 22 are turned on (Yes in S51) and the speed of thevehicle is equal to or higher than the second predetermined speed (Yesin S7), the low-beam headlights 21 and position lights 22 are turned on(S52). In other words, when the vehicle speeds up from crawling speed totraveling speed after the low-beam headlights 21 are turned off in S6,S27, or S36, the low-beam headlights 21 are turned on again. Thisprevents the vehicle from being forgotten to turn on being forgotten toturn on the low-beam headlights 21 again.

When the low-beam headlights 21 are turned off in S6 (FIG. 2 ), S27(FIG. 5 ), or S36 (FIG. 6 ) while the position lights 22 are turned on(Yes in S51) and the distance (travel distance) traveled since thelow-beam headlights 21 are turned off reaches the predetermined distanceor longer (Yes in S8), the low-beam headlights 21 and position lights 22are both turned on (S52 in FIG. 3 ). Even if the vehicle is moving atcrawling speed (Yes in S4 in FIG. 2 ), it could be hard for the driverto drive the vehicle with the low-beam headlights 21 off insemi-darkness (Yes in S2 in FIG. 2 ). The low-beam headlights 21 aretherefore turned on again when the vehicle travels a certain distancewith the low-beam headlights 21 off. This allows minimum travel of thevehicle with the low-beam headlights 21 off and prevents the vehiclefrom being forgotten to turn on the low-beam headlights 21.

When the low-beam headlights 21 are turned off while the position lights22 are turned on in S6 in FIG. 2 , S27 in FIG. 5 , or S36 in FIG. 6 (Yesin S51) and the position of the light switch 11 is then changed to theSMALL position 14 (Yes in S9), the low-beam headlights 21 and positionlights 22 are turned on (S52). From drivability perspective, it isdesirable that the driver is able to turn on the low-beam headlights 21again anytime the driver wants to. The light switch 11 is provided withthe HEADLIGHT position 15. When the position of the light switch 11 isset to the HEADLIGHT position 15, the low-beam headlights 21 andposition lights 22 are always on. However, the driver who drives thevehicle with the light switch 11 always set to the AUTO position 13 islikely to be unfamiliar with the HEADLIGHT position 15. As describedabove, the low-beam headlights 21 are turned on or off through the sameoperation to switch from the AUTO position 13 to the SMALL position 14(Yes in S5 in FIG. 2 and Yes in S9 in FIG. 3 ). This improves theoperability of the light switch 11.

When the low-beam headlights 21 are turned off while position lights 22are turned on in S6 in FIG. 2 , S27 in FIG. 5 , or S36 in FIG. 6 (Yes inS51) and the speed of the vehicle is equal to or higher than the thirdpredetermined speed (No in S12) or when the parking brake and park rangeare both off (No in S13), the third process in FIG. 4 cannot determinewhether to turn on or off the low-beam headlights 21 and position lights22 of the vehicle. In this case, when the position of the low-beam headswitch 11 is changed to the OFF position 12 in the second process ofFIG. 3 (Yes in S10), the low-beam headlights 21 remain off while theposition lights 22 remain on (S53). In other words, when the vehicle istraveling at a speed (equal to or higher than the third predeterminedspeed) not low enough that the vehicle is thought to be substantiallystopped or when the parking brake and park range are released, thevehicle is not stopped or is ready to start. Since the vehicle is movingor is ready to start, all the lights of the vehicle are not turned offeven when the light switch 11 is moved to the OFF position 12. When thevehicle is moving or is ready to start, therefore, the position lights22 are surely turned on, and this simultaneously ensures a certaindegree of visibility of the vehicle from surroundings.

In FIG. 4 , when the position of the light switch 11 is set to the AUTOposition 13 (Yes in S15), the brightness outside the vehicle is lowerthan the predetermined value (Yes in S14), the speed of the vehicle islower than the third predetermined speed (Yes in S12), at least one ofthe parking brake and park range is on (Yes in S13), and the position ofthe light switch 11 is changed to the OFF position 12 (Yes in S22 inFIG. 5 ), the low-beam headlights 21 and position lights 22 are turnedoff (S23). In other words, it is possible to turn off all the exteriorlights of the vehicle without causing any problem only when the vehicleis substantially stopped, at least one of the parking brake and parkrange is on, and the position of the light switch 11 is changed to theOFF position 12 by the driver. When the light switch 11 is moved to theOFF position 12 under the aforementioned conditions, therefore, thelow-beam headlights 21 and position lights 22 are able to be turned offthrough driver's switching operation. This allows all the exteriorlights to be turned off as needed.

In FIG. 5 , when the low-beam headlights 21 and position lights 22 areturned off (S23) and the speed of the vehicle then increases to the fourpredetermined speed or higher (Yes in S26), the position lights 22 areturned on while the low-beam headlights 21 remain off (S27). When allthe exterior lights of the vehicle are turned off in the situation whereno problem could be caused if all of the exterior lights of the vehicleare turned off as described above and the vehicle which has beensubstantially stopped starts to move at crawling speed, the positionlights 22 are turned on first. In other words, when the vehicle isstopped, it may be assumed that there are obstacles, such as walls,around or near the vehicle. At starting, the vehicle will first crawlaway from the obstacles or the like and then speed up. In such asituation, the position lights 22 are turned on while the low-beamheadlights 21 remain off. This prevents light from the low-beamheadlights 21 from reflecting on the obstacles or the like therearoundand interfering with the driver's driving operation. Furthermore, theposition lights 22 are turned on when the vehicle is crawling, and thevehicle is thereby prevented from traveling with all the exterior lightsoff. This ensures a certain degree of visibility from surroundings ofthe vehicle which is traveling in the aforementioned situation.

In FIG. 5 , when the low-beam headlights 21 and position lights 22 areoff (S23) and the parking brake and park range are both turned off (Yesin S25), the position lights 22 are turned on while the low-beamheadlights 21 remain off (S27). In other words, when the vehicle isready to travel with the parking brake and park range released, theposition lights 22 are turned on. This prevents the vehicle fromstarting with all the exterior lights of the vehicle off.

In FIG. 2 , when the position of the light switch 11 is set to the AUTOposition 13 (Yes in S3), the brightness outside the vehicle is lowerthan the predetermined value (Yes in S66), and a failure of the speedsensor 33 is detected (No in S1), the low-beam headlights 21 andposition lights 22 are turned on (S11) even if the position of the lightswitch 11 is changed to the SMALL position 14 or OFF position 12 (S67).In other words, when the speed sensor 33 is detected to have failed, thelow-beam headlights 21 and position lights 22 are turned on. Even if theposition of the light switch 11 is then changed to the SMALL position 14or OFF position 12, the low-beam headlights 21 and position lights 22remain on. This serves as a fail-safe against a failure of the speedsensor 33. This prevents the vehicle from traveling with the low-beamheadlights 21 off.

In FIG. 4 , when the position of the light switch 11 is set to the AUTOposition 13 (Yes in S15), the brightness outside the vehicle is lowerthan the predetermined value (Yes in S14), and at least one of theparking brake sensor 63 and park-range sensor 65 has failed (No in S16),the low-beam headlights 21 and position lights 22 are turned on (S17).In other words, when at least one of the parking brake sensor 63 andpark-range sensor 65 has failed, the low-beam headlights 21 and positionlights 22 are turned on. This prevents the vehicle from traveling withthe low-beam headlights 21 off when these sensors have failed.

What is claimed is:
 1. A light system for a vehicle, comprising acombination switch set to a rotation position to be rotationally changedfor switching modes of a light that provides illumination outside,wherein the rotation position includes an AUTO position and a SMALLposition, the combination switch includes a mechanism which isconfigured to return the rotation position to the AUTO position when therotation position is changed to the SMALL position, the light includes alow-beam headlight and a position light, and the low-beam headlight isturned on when: a speed of the vehicle having the light system is lowerthan a first predetermined speed; the rotation position is then changedto the SMALL position to turn off the low-beam headlight; and a traveldistance of the vehicle since turn off of the low-beam headlight reachesa predetermined distance.
 2. The vehicle light system according to claim1, wherein the low-beam headlight is turned on when the speed of thevehicle reaches a second predetermined speed or higher before the traveldistance reaches the predetermined distance.